DETERMINATION OF SOME QUINOLONES IN TABLETS, HUMAN PLASMA AND URINE BY DIFFERENTIAL-PULSE POLAROGRAPHY

A differential pulse polarographic method was developed for the determination of norfloxacin, cinoxacin and pipemidic, oxolinic and piromidic acids in tablets and biological fluids. Well defined peaks, useful for an accurate and precise assay, were observed in the appropriate supporting electrolyte (Britton-Robinson and phosphate buffers), depending on both the kind of preparation (tablet, plasma or urine) and the quinolone investigated. The analysis of quinolones in biological fluids requires a prior clean-up procedure (treatment with acetonitrile and 2 M potassium hydroxide for plasma and solid-liquid extraction for urine) while common excipients were found not to interfere in the tablet assay. In each of the above situations (tablet, plasma or urine), good precision of the method evaluated as the CV, was found.